Level of patient contact and Impact of Event scores among Canadian healthcare providers during the COVID-19 pandemic

Background Healthcare providers (HCP) continue to provide patient care during the COVID-19 pandemic despite the known risks for transmission. Studies conducted early in the pandemic showed that factors associated with higher levels of distress among HCP included being of younger age, female, in close contact with people with COVID-19, and lower levels of education. The goal of this study was to determine if level of patient contact was associated with concern for post-traumatic stress disorder (PTSD) as measured by the Impact of Event Scale-Revised (IES-R). Methods This cross-sectional study, embedded within a prospective cohort study, recruited HCP working in hospitals in four Canadian provinces from June 2020 to June 2023. Data were collected at enrolment and annually from baseline surveys with the IES-R scale completed at withdrawal/study completion. Modified Poisson regression was used to determine the association between level of patient contact and concern for PTSD (i.e., IES-R scores ≥24). Results The adjusted rate ratio (RR) associated with concern for PTSD among HCP with physical contact/direct patient care was 1.19 (95% confidence interval (CI) 1.03, 1.38) times higher than for HCP with no direct contact. In fully adjusted linear regression models, physical care/contact was associated with higher avoidance and hyperarousal scores, but not intrusion scores. Conclusions Administrators and planners need to consider the impact of heightened and ongoing stress among HCP by providing early screening for adverse emotional outcomes and delivery of tailored preventive strategies to ensure immediate and long-term HCP health. Supplementary Information The online version contains supplementary material available at 10.1186/s12913-024-11426-w.


Background
Transmission of the SARS-CoV-2 coronavirus has continued since the World Health Organization (WHO) declared coronavirus disease 2019 (COVID-19) a pandemic on March 11, 2020 [1].Due to the significant physical health impacts of COVID-19, attempts were made to slow viral transmission including quarantine restrictions and preventive methods such as wearing masks, social distancing, closing venues, and vaccination.However, such mitigation strategies, added to the threats of the disease itself, can increase disruption and trauma-related stress [2,3].
Post-traumatic stress disorder (PTSD) is a common outcome after witnessing or experiencing a traumatic event [4].In a 2002 Canadian study based on selfreported symptoms, Van Ameringen et al. found that prevalence of PTSD was 2.4% [5].In a subsequent selfreported Canadian survey conducted between August and December 2021, the estimated prevalence of PTSD had increased to 5.4% [6].Despite ongoing transmission, healthcare providers (HCP) need to provide optimal patient care.During the early pandemic period higher stress levels were reported by HCP secondary to increased workload, constantly changing work environments, provision of care to people with COVID-19, deaths caused by the disease, and fear of infecting themselves and their close contacts [7,8].
Several studies [9][10][11][12][13][14][15] have used the Impact of Event Scale-Revised (IES-R) [16] to assess concern for PTSD during the COVID-19 pandemic.Among HCP, younger age, female gender, personal exposure to COVID-19, and lower levels of education have been identified as factors associated with higher levels of concern for PTSD [11,14,17].However, these studies were conducted over short periods and/or early in the pandemic when some transmission mitigation strategies, such as quarantine measures and vaccines, had either not been employed or were not yet available.
This study aims to investigate the level of concern for PTSD, as measured by the IES-R, among Canadian HCP in relation to their level of contact with patients, adjusted for potential confounders, between June 10, 2021 and December 1, 2023.Levels of avoidance, intrusion, and hyperarousal are also explored.

Study design
The COVID-19 Cohort Study was a 3. Consented participants completed annual baseline surveys and illness and vaccination surveys as needed.Participants completed the IES-R once within two weeks of study withdrawal or at study closure (December 1, 2023) (see Fig. 1).

Participants
Consented HCP were eligible for these analyses if they completed ≥ 50% of their most recent baseline questionnaire; were 18 to 75 years old, inclusive; were employed full-or part-time (> 20 h per week) by a participating hospital; or were a physician, midwife, or nurse practitioner with hospital privileges and who cared for ill patients ≥ 8 h per week.Participants with incomplete IES-R data were excluded from analyses.

Outcome
The Impact of Event Scale (IES) is a 15-item measure of the frequency with which respondents experience thoughts and behaviours associated with two definitional symptoms of PTSD: intrusion and avoidance [18].The scale was revised (IES-R) with the addition of another set of items designed to identify the frequency of hyperarousal symptoms [16].The IES-R asks participants to indicate, on a scale from 0 (not at all) to 4 (extremely), how distressing each of 22 listed difficulties have been for them during the previous seven days.To orient participants, the survey was introduced with "You have been working throughout the COVID-19 pandemic".Overall IES-R scores are the sum of all 22 items (range 0 to 88) and were interpreted using criteria developed by Weiss and Marmar [16] (0-23: no concern for PTSD; ≥ 24: indicative of concern for PTSD).Subscale scores (avoidance, intrusion, hyperarousal) are the mean of the subscale item scores (range 0 to 4).

Exposure
In the baseline survey, participants were asked to respond to three questions that asked them to indicate which of five levels of contact they had with inpatients, outpatients, and emergency department patients: 1) not applicable, no close contact with patients; 2) never or rarely in room or confined physical space with patients; 3) in room/confined space with patients, but not within 2 m of their face; 4) in room/confined space and within 2 m of their face, but no physical contact/care; 5) physical contact and/or care of patients.Two metres was selected as a key distance for this study as recommended by the Government of Canada to reduce transmission of COVID-19 [19].The highest level of contact in any of the three settings was selected.The four levels of patient contact used in these analyses are: 1) no direct contact; 2) never/rarely in patient rooms; 3) in patient rooms but no contact, and 4) physical care/contact.

Covariates
Baseline surveys collected demographic and work-related information including age; gender; self-reported health; medications for anxiety, depression, or insomnia; occupation; and current work unit (high-risk: emergency department, adult intensive care unit, or adult inpatient medical unit vs low-risk: all others).COVID-19 vaccine receipt was obtained from the most recent vaccination questionnaire.The study did not use information from the illness/testing surveys.
A mitigation strategy measure that ranked the intensity of non-pharmacological mitigation strategies associated with three sectors (work, education, and other locations) on a four-point scale (0: no restrictions to 3: most stringent restrictions) was included as a study covariate [20].The mutually exclusive categories developed by Akanteva et al. are specific to each sector (e.g., category 3: work: all non-essential workplaces closed or operating remotely, only essential services or businesses remain open; education: all schools closed for in-person instruction; other locations: stringent gathering restriction, border closures between provinces for non-essential travel, closure of all indoor activities, and closure of most outdoor activities) [20].Periods when restrictions summed to ≥7 were identified as periods of high mitigation.Periods were determined using Ontario data.While other provinces imposed different restrictions at different times, Ontario was selected as the referent as most study sites were within this province.

Data analysis
Chi-squared or Fisher's exact tests were used to compare categorical variables while t-tests or median tests were used to compared continuous variables, as appropriate.Modified Poisson regression was used to quantify the relationships between study variables and dichotomized IES-R scores [21].All models were adjusted by age and gender.Other study covariates that were not associated with the outcome were sequentially eliminated as per Vittinghoff et al. [22].Variance estimates were adjusted in multivariable models for clustering within province.The final model was assessed for goodness-of-fit and multi-collinearity.Linear regression, adjusted for clustering within provinces, was used to assess the association between subscale scores and variables found to be significant predictors of the dichotomized IES-R score.

Participant characteristics
Of the 2648 HCP who participated in the parent study, 1498 (56.6%) submitted an IES-R between June 10, 2021 and December 1, 2023.Those who submitted an IES-R were significantly older, and less likely to be a nurse, work on a high-risk unit, or to have been working for less than five years compared with the full cohort (see Table 1).  1 Pearson's chi-squared for binary/categorical variables, two-sided t-test for continuous variables 2 See definition [23] 3 No appropriate comparison available for the full-study population given that COVID-19 vaccination status was a time-varying factor 4 Adult intensive care units, emergency departments, and adult inpatient medical units 5 Respiratory therapist, laboratory technician, physical therapist, occupational therapist, imaging technician/technologist, pharmacist, pharmacy technician, psychologist, social worker 6  Almost one third of participants who completed the IES-R were nurses, nurse practitioners, or midwives, 773 (51.6%) provided physical care to patients, and 875 (58.4%) worked in the province of Ontario.The majority of participants were female (1309 or 87.3%) and had a mean age of 42.4 (95% confidence interval (CI) 41.9, 43.0) years.As gender was considered an important study covariate, those who selected "other" were dropped from analyses due to the small sample size.
The top three individual IES-R items most frequently assigned a score of 4, indicating that participants were extremely affected, were trouble staying asleep (n = 48/1498 or 3.2%), trouble falling asleep (n = 42), and trying not to think about it (n = 39).Meanwhile, few (n = 6) indicated they were extremely affected by reminders causing physical reactions, such as sweating, trouble breathing, nausea, or a pounding heart.
As shown in Table 2, median IES-R scores, mean subscale scores, and the percent of respondents with an IES-R score indicative of concern for PTSD were similar in 2021 and 2022 but decreased significantly in 2023 (p < 0.001).

Patient contact and concern for PTSD
As seen in Table 3, the unadjusted rate ratio (RR) associated with concern for PTSD among HCP with physical contact/care was 1.24 (95% CI 1.05 1.47) times higher than for HCP with no direct contact.When confounding variables were added, the adjusted RR associated with physical contact/care decreased by less than 5% to 1.19 (95% CI 1.03, 1.38).

Subscale scores
As shown in Table 2, the mean subscale scores were 0.87, 0.87, and 0.67 for avoidance, intrusion, and hyperarousal, respectively.As expected, given that subscale items are summed to create the overall IES-R score, the correlation between the IES-R score and each subscale was 0.92 for both avoidance and hyperarousal and 0.96 for intrusion, with no differences in correlations by year of survey completion.There was also high correlation between the subscale scores at 0.88 for intrusion:hyperarousal, 0.79 for intrusion:avoidance, and 0.74 for hyperarousal:avoidance.
In fully adjusted linear regression models, physical care/contact was associated with increased avoidance and hyperarousal scores, but not intrusion scores.Being in the same room as a patient was also associated with higher avoidance scores.

Discussion
Provision of physical care during the COVID-19 pandemic was associated with increased concern for PTSD among Canadian HCP.Between June 10, 2021 and December 1, 2023, in adjusted regression models, HCP providing physical care to patients had IES-R scores that were higher than for those with no direct patient contact.Patient contact was also associated with increased avoidance and hyperarousal scores but not with not with intrusion scores.
The association between level of patient contact and emotional distress has been found in previous studies.During the 2003 severe acute respiratory syndrome (SARS) outbreak in Toronto, nurses who had longer contact with patients with SARS had higher distress scores [24].Similar findings were reported very early in the COVID-19 pandemic (February 2020) in China where working in a frontline position (i.e., directly engaged in clinical activities with patients with elevated temperatures or confirmed to have COVID-19) was associated with significantly higher median IES-R scores (22.5) than those who were not (17.0)[13].
In this study, in 2023, 22.5% of HCP had scores indicative of concern for PTSD.This rate is significantly lower than the 47.8% with scores of concern in 2021 but is,  itself, substantially lower than estimates from other studies conducted with HCP that also used the IES-R with a cut-off score of ≥ 24.In a Canadian study, 74% of critical care nurses had scores of concern [25] while in Italy, 65% of physicians and 71% of nurses had scores of concern [26].However, the estimate from this study is in line with an earlier 2020 Ontario study that also used the IES-R with a cut-off score ≥ 24 that found 50% of HCP had scores suggestive of concern for PTSD [27].Fattori et al. [28] reported that Italian HCP mean IES-R scores decreased from 22 in 2020/2021 to 13 in 2021/2022.Although the scores are similar to the current study, the decrease in scores occurred about a year earlier in the Italian study.In contrast, Th'ng and colleagues reported substantially lower percentages of emergency department HCP who had scores of concern than in our study, at 13.6-16.2%for 2020 through 2022 in their longitudinal single-centre study in Singapore, with no significant change over time [29].
Studies indicate that HCP have dealt with COVID-19 associated stress in many ways.One in four Canadian HCP reported drinking more in 2021 than before the COVID-19 pandemic [30] and Canadian adults who screened positive for PTSD were 3.5 times more likely than those with a negative screen to report increased cannabis use since the beginning of the pandemic [31].Conversely, 70% of HCP indicated that they are exercising to improve or maintain their health during the pandemic [30].Carmassi et al. reported that HCP with IES-R scores of ≥ 24 had significantly higher Work and Social Adjustment Scale [32] scores than HCP with lower scores [33], indicating interference in working, recreational, and social activities, household chores, and family relationships.A rapid review of successful strategies to reduce HCP stress indicated that actions need to be taken at the organizational level [34].These authors suggest that communication needs to be timely and accurate, and that HCP safety and well-being needs to be kept in the forefront.Healthcare leaders should tailor stress reduction strategies to their population and prioritize HCP who are providing direct patient care.
As with all studies, this study has limitations.Non-random sampling methods were used to generate both the study and the sub-study populations; study participants were self-selected, and some did not complete the IES-R.Biases stemming from differential patterns of study enrollment or attrition could have led to under-or overestimates of the relationship between level of patient contact and symptoms associated with concern for PTSD.It is unknown if we over-or under-sampled HCP with PTSD symptoms (% of participants with symptoms indicative of concern for PTSD; current study 2021: 47.8%; 2020 Honarmand et al. [27]: 50%; 2021 Crowe et al. [25]: 74%; 2021 Gorini et al.: 65% (physicians) [26]).In addition, the overall variance explained by all regression models was low which is likely due to unmeasured known (e.g., pre-existing mental illness [35], fear of COVID-19 [36], personality [37]), and unknown covariates/confounders/mediators.As well, all results are self-reported and may suffer from social desirability bias.Although we have no data from before (nor early) in the pandemic, one strength of the study is its longitudinal nature, with data from 2021 through 2023.Another strength is that participants were from four provinces across Canada, increasing generalizability.

Conclusion
HCP who provided direct patient care were significantly more likely to have IES-R scores indicative of concern for PTSD than those reporting no direct patient contact.Healthcare system administrators and planners must consider the high prevalence of concern for PTSD among HCP who worked during the COVID-19 pandemic when reflecting on current human health resources.Early screening for adverse emotional outcomes during stressful times followed by the delivery of timely, tailored preventive strategies is vital for both immediate and long-term HCP health.
5 year prospective cohort study following HCP from acute care, rehabilitation, and complex care hospitals in the greater Toronto area (Sinai Health, Sunnybrook Health Sciences Centre, Oak Valley Health (Markham Stouffville Hospital), North York General, Michael Garron Hospital, Unity Health (St.Michael's Hospital), William Osler Health System, and University Health Network), Hamilton (St.Joseph's Healthcare Hamilton, Hamilton Health Sciences Centre), Ottawa (The Ottawa Hospital), Alberta (Calgary Health Zone, Grey Nuns Community Hospital, University of Alberta Hospital), Quebec (Centre hospitalier universitaire de Sherbrooke), and Halifax (IWK Health Centre, QE II) as well as private physician or midwifery practices in the Toronto area.Rolling enrollment, from June 2020 to June 2023, occurred following ethical approval at each site.

Table 2
Crude IES-R and subscale scores for Canadian healthcare providers, June 10, 2021-December 1, 2023, by calendar year Median test for IES-R scores over time: p < 0.001 a median (interquartile range) as IES-R scores were not normally distributed b number (percent) c mean (95% confidence interval)

Table 3
Factor-specific and modified Poisson regression model estimates comparing IES-R scores of no concern (<24) versus of concern (≥24), Canadian healthcare providers (June 10, 2021-December 1, 2023) d Respiratory therapist, laboratory technician, physical therapist, occupational therapist, imaging technician/technologist, pharmacist, pharmacy technician, psychologist, social worker e Infection prevention and control practitioner, food service, ward clerk, administration, healthcare aide, housekeeper, porter, researcher, other clinical support f These variables are included in the adjusted modified Poisson regression model to reduce confounding in the relationship between level of patient contact and dichotomous IES-R scores and should not be interpreted as adjusted main effects, or predictors, in their own right